forked from zlib-ng/zlib-ng
-
Notifications
You must be signed in to change notification settings - Fork 0
/
inflate.c
1408 lines (1280 loc) · 49.3 KB
/
inflate.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/* inflate.c -- zlib decompression
* Copyright (C) 1995-2022 Mark Adler
* For conditions of distribution and use, see copyright notice in zlib.h
*/
#include "zbuild.h"
#include "zutil.h"
#include "inftrees.h"
#include "inflate.h"
#include "inflate_p.h"
#include "inffixed_tbl.h"
#include "functable.h"
/* Avoid conflicts with zlib.h macros */
#ifdef ZLIB_COMPAT
# undef inflateInit
# undef inflateInit2
#endif
/* function prototypes */
static int inflateStateCheck(PREFIX3(stream) *strm);
static int updatewindow(PREFIX3(stream) *strm, const uint8_t *end, uint32_t len, int32_t cksum);
static uint32_t syncsearch(uint32_t *have, const unsigned char *buf, uint32_t len);
static inline void inf_chksum_cpy(PREFIX3(stream) *strm, uint8_t *dst,
const uint8_t *src, uint32_t copy) {
if (!copy) return;
struct inflate_state *state = (struct inflate_state*)strm->state;
#ifdef GUNZIP
if (state->flags) {
functable.crc32_fold_copy(&state->crc_fold, dst, src, copy);
} else
#endif
{
strm->adler = state->check = functable.adler32_fold_copy(state->check, dst, src, copy);
}
}
static inline void inf_chksum(PREFIX3(stream) *strm, const uint8_t *src, uint32_t len) {
struct inflate_state *state = (struct inflate_state*)strm->state;
#ifdef GUNZIP
if (state->flags) {
functable.crc32_fold(&state->crc_fold, src, len, 0);
} else
#endif
{
strm->adler = state->check = functable.adler32(state->check, src, len);
}
}
static int inflateStateCheck(PREFIX3(stream) *strm) {
struct inflate_state *state;
if (strm == NULL || strm->zalloc == NULL || strm->zfree == NULL)
return 1;
state = (struct inflate_state *)strm->state;
if (state == NULL || state->strm != strm || state->mode < HEAD || state->mode > SYNC)
return 1;
return 0;
}
int32_t Z_EXPORT PREFIX(inflateResetKeep)(PREFIX3(stream) *strm) {
struct inflate_state *state;
if (inflateStateCheck(strm))
return Z_STREAM_ERROR;
state = (struct inflate_state *)strm->state;
strm->total_in = strm->total_out = state->total = 0;
strm->msg = NULL;
if (state->wrap) /* to support ill-conceived Java test suite */
strm->adler = state->wrap & 1;
state->mode = HEAD;
state->check = ADLER32_INITIAL_VALUE;
state->last = 0;
state->havedict = 0;
state->flags = -1;
state->dmax = 32768U;
state->head = NULL;
state->hold = 0;
state->bits = 0;
state->lencode = state->distcode = state->next = state->codes;
state->sane = 1;
state->back = -1;
INFLATE_RESET_KEEP_HOOK(strm); /* hook for IBM Z DFLTCC */
Tracev((stderr, "inflate: reset\n"));
return Z_OK;
}
int32_t Z_EXPORT PREFIX(inflateReset)(PREFIX3(stream) *strm) {
struct inflate_state *state;
if (inflateStateCheck(strm))
return Z_STREAM_ERROR;
state = (struct inflate_state *)strm->state;
state->wsize = 0;
state->whave = 0;
state->wnext = 0;
return PREFIX(inflateResetKeep)(strm);
}
int32_t Z_EXPORT PREFIX(inflateReset2)(PREFIX3(stream) *strm, int32_t windowBits) {
int wrap;
struct inflate_state *state;
/* get the state */
if (inflateStateCheck(strm))
return Z_STREAM_ERROR;
state = (struct inflate_state *)strm->state;
/* extract wrap request from windowBits parameter */
if (windowBits < 0) {
wrap = 0;
if (windowBits < -MAX_WBITS)
return Z_STREAM_ERROR;
windowBits = -windowBits;
} else {
wrap = (windowBits >> 4) + 5;
#ifdef GUNZIP
if (windowBits < 48)
windowBits &= MAX_WBITS;
#endif
}
/* set number of window bits, free window if different */
if (windowBits && (windowBits < MIN_WBITS || windowBits > MAX_WBITS))
return Z_STREAM_ERROR;
if (state->window != NULL && state->wbits != (unsigned)windowBits) {
ZFREE_WINDOW(strm, state->window);
state->window = NULL;
}
/* update state and reset the rest of it */
state->wrap = wrap;
state->wbits = (unsigned)windowBits;
return PREFIX(inflateReset)(strm);
}
/* This function is hidden in ZLIB_COMPAT builds. */
int32_t ZNG_CONDEXPORT PREFIX(inflateInit2)(PREFIX3(stream) *strm, int32_t windowBits) {
int32_t ret;
struct inflate_state *state;
if (strm == NULL)
return Z_STREAM_ERROR;
strm->msg = NULL; /* in case we return an error */
if (strm->zalloc == NULL) {
strm->zalloc = PREFIX(zcalloc);
strm->opaque = NULL;
}
if (strm->zfree == NULL)
strm->zfree = PREFIX(zcfree);
state = ZALLOC_INFLATE_STATE(strm);
if (state == NULL)
return Z_MEM_ERROR;
Tracev((stderr, "inflate: allocated\n"));
strm->state = (struct internal_state *)state;
state->strm = strm;
state->window = NULL;
state->mode = HEAD; /* to pass state test in inflateReset2() */
state->chunksize = functable.chunksize();
ret = PREFIX(inflateReset2)(strm, windowBits);
if (ret != Z_OK) {
ZFREE_STATE(strm, state);
strm->state = NULL;
}
return ret;
}
#ifndef ZLIB_COMPAT
int32_t Z_EXPORT PREFIX(inflateInit)(PREFIX3(stream) *strm) {
return PREFIX(inflateInit2)(strm, DEF_WBITS);
}
#endif
/* Function used by zlib.h and zlib-ng version 2.0 macros */
int32_t Z_EXPORT PREFIX(inflateInit_)(PREFIX3(stream) *strm, const char *version, int32_t stream_size) {
if (CHECK_VER_STSIZE(version, stream_size))
return Z_VERSION_ERROR;
return PREFIX(inflateInit2)(strm, DEF_WBITS);
}
/* Function used by zlib.h and zlib-ng version 2.0 macros */
int32_t Z_EXPORT PREFIX(inflateInit2_)(PREFIX3(stream) *strm, int32_t windowBits, const char *version, int32_t stream_size) {
if (CHECK_VER_STSIZE(version, stream_size))
return Z_VERSION_ERROR;
return PREFIX(inflateInit2)(strm, windowBits);
}
int32_t Z_EXPORT PREFIX(inflatePrime)(PREFIX3(stream) *strm, int32_t bits, int32_t value) {
struct inflate_state *state;
if (inflateStateCheck(strm))
return Z_STREAM_ERROR;
if (bits == 0)
return Z_OK;
INFLATE_PRIME_HOOK(strm, bits, value); /* hook for IBM Z DFLTCC */
state = (struct inflate_state *)strm->state;
if (bits < 0) {
state->hold = 0;
state->bits = 0;
return Z_OK;
}
if (bits > 16 || state->bits + (unsigned int)bits > 32)
return Z_STREAM_ERROR;
value &= (1L << bits) - 1;
state->hold += (unsigned)value << state->bits;
state->bits += (unsigned int)bits;
return Z_OK;
}
/*
Return state with length and distance decoding tables and index sizes set to
fixed code decoding. This returns fixed tables from inffixed_tbl.h.
*/
void Z_INTERNAL PREFIX(fixedtables)(struct inflate_state *state) {
state->lencode = lenfix;
state->lenbits = 9;
state->distcode = distfix;
state->distbits = 5;
}
int Z_INTERNAL PREFIX(inflate_ensure_window)(struct inflate_state *state) {
/* if it hasn't been done already, allocate space for the window */
if (state->window == NULL) {
unsigned wsize = 1U << state->wbits;
state->window = (unsigned char *)ZALLOC_WINDOW(state->strm, wsize + state->chunksize, sizeof(unsigned char));
if (state->window == NULL)
return Z_MEM_ERROR;
#ifdef Z_MEMORY_SANITIZER
/* This is _not_ to subvert the memory sanitizer but to instead unposion some
data we willingly and purposefully load uninitialized into vector registers
in order to safely read the last < chunksize bytes of the window. */
__msan_unpoison(state->window + wsize, state->chunksize);
#endif
}
/* if window not in use yet, initialize */
if (state->wsize == 0) {
state->wsize = 1U << state->wbits;
state->wnext = 0;
state->whave = 0;
}
return Z_OK;
}
/*
Update the window with the last wsize (normally 32K) bytes written before
returning. If window does not exist yet, create it. This is only called
when a window is already in use, or when output has been written during this
inflate call, but the end of the deflate stream has not been reached yet.
It is also called to create a window for dictionary data when a dictionary
is loaded.
Providing output buffers larger than 32K to inflate() should provide a speed
advantage, since only the last 32K of output is copied to the sliding window
upon return from inflate(), and since all distances after the first 32K of
output will fall in the output data, making match copies simpler and faster.
The advantage may be dependent on the size of the processor's data caches.
*/
static int32_t updatewindow(PREFIX3(stream) *strm, const uint8_t *end, uint32_t len, int32_t cksum) {
struct inflate_state *state;
uint32_t dist;
state = (struct inflate_state *)strm->state;
if (PREFIX(inflate_ensure_window)(state)) return 1;
/* len state->wsize or less output bytes into the circular window */
if (len >= state->wsize) {
/* Only do this if the caller specifies to checksum bytes AND the platform requires
* it (s/390 being the primary exception to this. Also, for now, do the adler checksums
* if not a gzip based header. The inline adler checksums will come in the near future,
* possibly the next commit */
if (INFLATE_NEED_CHECKSUM(strm) && cksum) {
/* We have to split the checksum over non-copied and copied bytes */
if (len > state->wsize)
inf_chksum(strm, end - len, len - state->wsize);
inf_chksum_cpy(strm, state->window, end - state->wsize, state->wsize);
} else {
memcpy(state->window, end - state->wsize, state->wsize);
}
state->wnext = 0;
state->whave = state->wsize;
} else {
dist = state->wsize - state->wnext;
/* Only do this if the caller specifies to checksum bytes AND the platform requires
* We need to maintain the correct order here for the checksum */
dist = MIN(dist, len);
if (INFLATE_NEED_CHECKSUM(strm) && cksum) {
inf_chksum_cpy(strm, state->window + state->wnext, end - len, dist);
} else {
memcpy(state->window + state->wnext, end - len, dist);
}
len -= dist;
if (len) {
if (INFLATE_NEED_CHECKSUM(strm) && cksum) {
inf_chksum_cpy(strm, state->window, end - len, len);
} else {
memcpy(state->window, end - len, len);
}
state->wnext = len;
state->whave = state->wsize;
} else {
state->wnext += dist;
if (state->wnext == state->wsize)
state->wnext = 0;
if (state->whave < state->wsize)
state->whave += dist;
}
}
return 0;
}
/*
Private macros for inflate()
Look in inflate_p.h for macros shared with inflateBack()
*/
/* Get a byte of input into the bit accumulator, or return from inflate() if there is no input available. */
#define PULLBYTE() \
do { \
if (have == 0) goto inf_leave; \
have--; \
hold += ((unsigned)(*next++) << bits); \
bits += 8; \
} while (0)
/*
inflate() uses a state machine to process as much input data and generate as
much output data as possible before returning. The state machine is
structured roughly as follows:
for (;;) switch (state) {
...
case STATEn:
if (not enough input data or output space to make progress)
return;
... make progress ...
state = STATEm;
break;
...
}
so when inflate() is called again, the same case is attempted again, and
if the appropriate resources are provided, the machine proceeds to the
next state. The NEEDBITS() macro is usually the way the state evaluates
whether it can proceed or should return. NEEDBITS() does the return if
the requested bits are not available. The typical use of the BITS macros
is:
NEEDBITS(n);
... do something with BITS(n) ...
DROPBITS(n);
where NEEDBITS(n) either returns from inflate() if there isn't enough
input left to load n bits into the accumulator, or it continues. BITS(n)
gives the low n bits in the accumulator. When done, DROPBITS(n) drops
the low n bits off the accumulator. INITBITS() clears the accumulator
and sets the number of available bits to zero. BYTEBITS() discards just
enough bits to put the accumulator on a byte boundary. After BYTEBITS()
and a NEEDBITS(8), then BITS(8) would return the next byte in the stream.
NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return
if there is no input available. The decoding of variable length codes uses
PULLBYTE() directly in order to pull just enough bytes to decode the next
code, and no more.
Some states loop until they get enough input, making sure that enough
state information is maintained to continue the loop where it left off
if NEEDBITS() returns in the loop. For example, want, need, and keep
would all have to actually be part of the saved state in case NEEDBITS()
returns:
case STATEw:
while (want < need) {
NEEDBITS(n);
keep[want++] = BITS(n);
DROPBITS(n);
}
state = STATEx;
case STATEx:
As shown above, if the next state is also the next case, then the break
is omitted.
A state may also return if there is not enough output space available to
complete that state. Those states are copying stored data, writing a
literal byte, and copying a matching string.
When returning, a "goto inf_leave" is used to update the total counters,
update the check value, and determine whether any progress has been made
during that inflate() call in order to return the proper return code.
Progress is defined as a change in either strm->avail_in or strm->avail_out.
When there is a window, goto inf_leave will update the window with the last
output written. If a goto inf_leave occurs in the middle of decompression
and there is no window currently, goto inf_leave will create one and copy
output to the window for the next call of inflate().
In this implementation, the flush parameter of inflate() only affects the
return code (per zlib.h). inflate() always writes as much as possible to
strm->next_out, given the space available and the provided input--the effect
documented in zlib.h of Z_SYNC_FLUSH. Furthermore, inflate() always defers
the allocation of and copying into a sliding window until necessary, which
provides the effect documented in zlib.h for Z_FINISH when the entire input
stream available. So the only thing the flush parameter actually does is:
when flush is set to Z_FINISH, inflate() cannot return Z_OK. Instead it
will return Z_BUF_ERROR if it has not reached the end of the stream.
*/
int32_t Z_EXPORT PREFIX(inflate)(PREFIX3(stream) *strm, int32_t flush) {
struct inflate_state *state;
const unsigned char *next; /* next input */
unsigned char *put; /* next output */
unsigned have, left; /* available input and output */
uint32_t hold; /* bit buffer */
unsigned bits; /* bits in bit buffer */
uint32_t in, out; /* save starting available input and output */
unsigned copy; /* number of stored or match bytes to copy */
unsigned char *from; /* where to copy match bytes from */
code here; /* current decoding table entry */
code last; /* parent table entry */
unsigned len; /* length to copy for repeats, bits to drop */
int32_t ret; /* return code */
#ifdef GUNZIP
unsigned char hbuf[4]; /* buffer for gzip header crc calculation */
#endif
static const uint16_t order[19] = /* permutation of code lengths */
{16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
if (inflateStateCheck(strm) || strm->next_out == NULL ||
(strm->next_in == NULL && strm->avail_in != 0))
return Z_STREAM_ERROR;
state = (struct inflate_state *)strm->state;
if (state->mode == TYPE) /* skip check */
state->mode = TYPEDO;
LOAD();
in = have;
out = left;
ret = Z_OK;
for (;;)
switch (state->mode) {
case HEAD:
if (state->wrap == 0) {
state->mode = TYPEDO;
break;
}
NEEDBITS(16);
#ifdef GUNZIP
if ((state->wrap & 2) && hold == 0x8b1f) { /* gzip header */
if (state->wbits == 0)
state->wbits = MAX_WBITS;
state->check = CRC32_INITIAL_VALUE;
CRC2(state->check, hold);
INITBITS();
state->mode = FLAGS;
break;
}
if (state->head != NULL)
state->head->done = -1;
if (!(state->wrap & 1) || /* check if zlib header allowed */
#else
if (
#endif
((BITS(8) << 8) + (hold >> 8)) % 31) {
SET_BAD("incorrect header check");
break;
}
if (BITS(4) != Z_DEFLATED) {
SET_BAD("unknown compression method");
break;
}
DROPBITS(4);
len = BITS(4) + 8;
if (state->wbits == 0)
state->wbits = len;
if (len > MAX_WBITS || len > state->wbits) {
SET_BAD("invalid window size");
break;
}
state->dmax = 1U << len;
state->flags = 0; /* indicate zlib header */
Tracev((stderr, "inflate: zlib header ok\n"));
strm->adler = state->check = ADLER32_INITIAL_VALUE;
state->mode = hold & 0x200 ? DICTID : TYPE;
INITBITS();
break;
#ifdef GUNZIP
case FLAGS:
NEEDBITS(16);
state->flags = (int)(hold);
if ((state->flags & 0xff) != Z_DEFLATED) {
SET_BAD("unknown compression method");
break;
}
if (state->flags & 0xe000) {
SET_BAD("unknown header flags set");
break;
}
if (state->head != NULL)
state->head->text = (int)((hold >> 8) & 1);
if ((state->flags & 0x0200) && (state->wrap & 4))
CRC2(state->check, hold);
INITBITS();
state->mode = TIME;
Z_FALLTHROUGH;
case TIME:
NEEDBITS(32);
if (state->head != NULL)
state->head->time = hold;
if ((state->flags & 0x0200) && (state->wrap & 4))
CRC4(state->check, hold);
INITBITS();
state->mode = OS;
Z_FALLTHROUGH;
case OS:
NEEDBITS(16);
if (state->head != NULL) {
state->head->xflags = (int)(hold & 0xff);
state->head->os = (int)(hold >> 8);
}
if ((state->flags & 0x0200) && (state->wrap & 4))
CRC2(state->check, hold);
INITBITS();
state->mode = EXLEN;
Z_FALLTHROUGH;
case EXLEN:
if (state->flags & 0x0400) {
NEEDBITS(16);
state->length = (uint16_t)hold;
if (state->head != NULL)
state->head->extra_len = (uint16_t)hold;
if ((state->flags & 0x0200) && (state->wrap & 4))
CRC2(state->check, hold);
INITBITS();
} else if (state->head != NULL) {
state->head->extra = NULL;
}
state->mode = EXTRA;
Z_FALLTHROUGH;
case EXTRA:
if (state->flags & 0x0400) {
copy = state->length;
if (copy > have)
copy = have;
if (copy) {
if (state->head != NULL && state->head->extra != NULL) {
len = state->head->extra_len - state->length;
if (len < state->head->extra_max) {
memcpy(state->head->extra + len, next,
len + copy > state->head->extra_max ?
state->head->extra_max - len : copy);
}
}
if ((state->flags & 0x0200) && (state->wrap & 4)) {
state->check = PREFIX(crc32)(state->check, next, copy);
}
have -= copy;
next += copy;
state->length -= copy;
}
if (state->length)
goto inf_leave;
}
state->length = 0;
state->mode = NAME;
Z_FALLTHROUGH;
case NAME:
if (state->flags & 0x0800) {
if (have == 0) goto inf_leave;
copy = 0;
do {
len = (unsigned)(next[copy++]);
if (state->head != NULL && state->head->name != NULL && state->length < state->head->name_max)
state->head->name[state->length++] = (unsigned char)len;
} while (len && copy < have);
if ((state->flags & 0x0200) && (state->wrap & 4))
state->check = PREFIX(crc32)(state->check, next, copy);
have -= copy;
next += copy;
if (len)
goto inf_leave;
} else if (state->head != NULL) {
state->head->name = NULL;
}
state->length = 0;
state->mode = COMMENT;
Z_FALLTHROUGH;
case COMMENT:
if (state->flags & 0x1000) {
if (have == 0) goto inf_leave;
copy = 0;
do {
len = (unsigned)(next[copy++]);
if (state->head != NULL && state->head->comment != NULL
&& state->length < state->head->comm_max)
state->head->comment[state->length++] = (unsigned char)len;
} while (len && copy < have);
if ((state->flags & 0x0200) && (state->wrap & 4))
state->check = PREFIX(crc32)(state->check, next, copy);
have -= copy;
next += copy;
if (len)
goto inf_leave;
} else if (state->head != NULL) {
state->head->comment = NULL;
}
state->mode = HCRC;
Z_FALLTHROUGH;
case HCRC:
if (state->flags & 0x0200) {
NEEDBITS(16);
if ((state->wrap & 4) && hold != (state->check & 0xffff)) {
SET_BAD("header crc mismatch");
break;
}
INITBITS();
}
if (state->head != NULL) {
state->head->hcrc = (int)((state->flags >> 9) & 1);
state->head->done = 1;
}
/* compute crc32 checksum if not in raw mode */
if ((state->wrap & 4) && state->flags)
strm->adler = state->check = functable.crc32_fold_reset(&state->crc_fold);
state->mode = TYPE;
break;
#endif
case DICTID:
NEEDBITS(32);
strm->adler = state->check = ZSWAP32(hold);
INITBITS();
state->mode = DICT;
Z_FALLTHROUGH;
case DICT:
if (state->havedict == 0) {
RESTORE();
return Z_NEED_DICT;
}
strm->adler = state->check = ADLER32_INITIAL_VALUE;
state->mode = TYPE;
Z_FALLTHROUGH;
case TYPE:
if (flush == Z_BLOCK || flush == Z_TREES)
goto inf_leave;
Z_FALLTHROUGH;
case TYPEDO:
/* determine and dispatch block type */
INFLATE_TYPEDO_HOOK(strm, flush); /* hook for IBM Z DFLTCC */
if (state->last) {
BYTEBITS();
state->mode = CHECK;
break;
}
NEEDBITS(3);
state->last = BITS(1);
DROPBITS(1);
switch (BITS(2)) {
case 0: /* stored block */
Tracev((stderr, "inflate: stored block%s\n", state->last ? " (last)" : ""));
state->mode = STORED;
break;
case 1: /* fixed block */
PREFIX(fixedtables)(state);
Tracev((stderr, "inflate: fixed codes block%s\n", state->last ? " (last)" : ""));
state->mode = LEN_; /* decode codes */
if (flush == Z_TREES) {
DROPBITS(2);
goto inf_leave;
}
break;
case 2: /* dynamic block */
Tracev((stderr, "inflate: dynamic codes block%s\n", state->last ? " (last)" : ""));
state->mode = TABLE;
break;
case 3:
SET_BAD("invalid block type");
}
DROPBITS(2);
break;
case STORED:
/* get and verify stored block length */
BYTEBITS(); /* go to byte boundary */
NEEDBITS(32);
if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
SET_BAD("invalid stored block lengths");
break;
}
state->length = (uint16_t)hold;
Tracev((stderr, "inflate: stored length %u\n", state->length));
INITBITS();
state->mode = COPY_;
if (flush == Z_TREES)
goto inf_leave;
Z_FALLTHROUGH;
case COPY_:
state->mode = COPY;
Z_FALLTHROUGH;
case COPY:
/* copy stored block from input to output */
copy = state->length;
if (copy) {
copy = MIN(copy, have);
copy = MIN(copy, left);
if (copy == 0)
goto inf_leave;
memcpy(put, next, copy);
have -= copy;
next += copy;
left -= copy;
put += copy;
state->length -= copy;
break;
}
Tracev((stderr, "inflate: stored end\n"));
state->mode = TYPE;
break;
case TABLE:
/* get dynamic table entries descriptor */
NEEDBITS(14);
state->nlen = BITS(5) + 257;
DROPBITS(5);
state->ndist = BITS(5) + 1;
DROPBITS(5);
state->ncode = BITS(4) + 4;
DROPBITS(4);
#ifndef PKZIP_BUG_WORKAROUND
if (state->nlen > 286 || state->ndist > 30) {
SET_BAD("too many length or distance symbols");
break;
}
#endif
Tracev((stderr, "inflate: table sizes ok\n"));
state->have = 0;
state->mode = LENLENS;
Z_FALLTHROUGH;
case LENLENS:
/* get code length code lengths (not a typo) */
while (state->have < state->ncode) {
NEEDBITS(3);
state->lens[order[state->have++]] = (uint16_t)BITS(3);
DROPBITS(3);
}
while (state->have < 19)
state->lens[order[state->have++]] = 0;
state->next = state->codes;
state->lencode = (const code *)(state->next);
state->lenbits = 7;
ret = zng_inflate_table(CODES, state->lens, 19, &(state->next), &(state->lenbits), state->work);
if (ret) {
SET_BAD("invalid code lengths set");
break;
}
Tracev((stderr, "inflate: code lengths ok\n"));
state->have = 0;
state->mode = CODELENS;
Z_FALLTHROUGH;
case CODELENS:
/* get length and distance code code lengths */
while (state->have < state->nlen + state->ndist) {
for (;;) {
here = state->lencode[BITS(state->lenbits)];
if (here.bits <= bits) break;
PULLBYTE();
}
if (here.val < 16) {
DROPBITS(here.bits);
state->lens[state->have++] = here.val;
} else {
if (here.val == 16) {
NEEDBITS(here.bits + 2);
DROPBITS(here.bits);
if (state->have == 0) {
SET_BAD("invalid bit length repeat");
break;
}
len = state->lens[state->have - 1];
copy = 3 + BITS(2);
DROPBITS(2);
} else if (here.val == 17) {
NEEDBITS(here.bits + 3);
DROPBITS(here.bits);
len = 0;
copy = 3 + BITS(3);
DROPBITS(3);
} else {
NEEDBITS(here.bits + 7);
DROPBITS(here.bits);
len = 0;
copy = 11 + BITS(7);
DROPBITS(7);
}
if (state->have + copy > state->nlen + state->ndist) {
SET_BAD("invalid bit length repeat");
break;
}
while (copy) {
--copy;
state->lens[state->have++] = (uint16_t)len;
}
}
}
/* handle error breaks in while */
if (state->mode == BAD)
break;
/* check for end-of-block code (better have one) */
if (state->lens[256] == 0) {
SET_BAD("invalid code -- missing end-of-block");
break;
}
/* build code tables -- note: do not change the lenbits or distbits
values here (10 and 9) without reading the comments in inftrees.h
concerning the ENOUGH constants, which depend on those values */
state->next = state->codes;
state->lencode = (const code *)(state->next);
state->lenbits = 10;
ret = zng_inflate_table(LENS, state->lens, state->nlen, &(state->next), &(state->lenbits), state->work);
if (ret) {
SET_BAD("invalid literal/lengths set");
break;
}
state->distcode = (const code *)(state->next);
state->distbits = 9;
ret = zng_inflate_table(DISTS, state->lens + state->nlen, state->ndist,
&(state->next), &(state->distbits), state->work);
if (ret) {
SET_BAD("invalid distances set");
break;
}
Tracev((stderr, "inflate: codes ok\n"));
state->mode = LEN_;
if (flush == Z_TREES)
goto inf_leave;
Z_FALLTHROUGH;
case LEN_:
state->mode = LEN;
Z_FALLTHROUGH;
case LEN:
/* use inflate_fast() if we have enough input and output */
if (have >= INFLATE_FAST_MIN_HAVE && left >= INFLATE_FAST_MIN_LEFT) {
RESTORE();
functable.inflate_fast(strm, out);
LOAD();
if (state->mode == TYPE)
state->back = -1;
break;
}
state->back = 0;
/* get a literal, length, or end-of-block code */
for (;;) {
here = state->lencode[BITS(state->lenbits)];
if (here.bits <= bits)
break;
PULLBYTE();
}
if (here.op && (here.op & 0xf0) == 0) {
last = here;
for (;;) {
here = state->lencode[last.val + (BITS(last.bits + last.op) >> last.bits)];
if ((unsigned)last.bits + (unsigned)here.bits <= bits)
break;
PULLBYTE();
}
DROPBITS(last.bits);
state->back += last.bits;
}
DROPBITS(here.bits);
state->back += here.bits;
state->length = here.val;
/* process literal */
if ((int)(here.op) == 0) {
Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
"inflate: literal '%c'\n" :
"inflate: literal 0x%02x\n", here.val));
state->mode = LIT;
break;
}
/* process end of block */
if (here.op & 32) {
Tracevv((stderr, "inflate: end of block\n"));
state->back = -1;
state->mode = TYPE;
break;
}
/* invalid code */
if (here.op & 64) {
SET_BAD("invalid literal/length code");
break;
}
/* length code */
state->extra = (here.op & MAX_BITS);
state->mode = LENEXT;
Z_FALLTHROUGH;
case LENEXT:
/* get extra bits, if any */
if (state->extra) {
NEEDBITS(state->extra);
state->length += BITS(state->extra);
DROPBITS(state->extra);
state->back += state->extra;
}
Tracevv((stderr, "inflate: length %u\n", state->length));
state->was = state->length;
state->mode = DIST;
Z_FALLTHROUGH;
case DIST:
/* get distance code */
for (;;) {
here = state->distcode[BITS(state->distbits)];
if (here.bits <= bits)
break;
PULLBYTE();
}
if ((here.op & 0xf0) == 0) {
last = here;
for (;;) {
here = state->distcode[last.val + (BITS(last.bits + last.op) >> last.bits)];
if ((unsigned)last.bits + (unsigned)here.bits <= bits)
break;
PULLBYTE();
}
DROPBITS(last.bits);
state->back += last.bits;
}
DROPBITS(here.bits);
state->back += here.bits;
if (here.op & 64) {
SET_BAD("invalid distance code");
break;
}
state->offset = here.val;
state->extra = (here.op & MAX_BITS);
state->mode = DISTEXT;
Z_FALLTHROUGH;
case DISTEXT:
/* get distance extra bits, if any */
if (state->extra) {
NEEDBITS(state->extra);
state->offset += BITS(state->extra);
DROPBITS(state->extra);
state->back += state->extra;
}
#ifdef INFLATE_STRICT
if (state->offset > state->dmax) {
SET_BAD("invalid distance too far back");
break;
}
#endif
Tracevv((stderr, "inflate: distance %u\n", state->offset));
state->mode = MATCH;
Z_FALLTHROUGH;
case MATCH:
/* copy match from window to output */
if (left == 0)
goto inf_leave;
copy = out - left;
if (state->offset > copy) { /* copy from window */
copy = state->offset - copy;
if (copy > state->whave) {
if (state->sane) {
SET_BAD("invalid distance too far back");
break;
}
#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
Trace((stderr, "inflate.c too far\n"));
copy -= state->whave;